Raspberries also contain antioxidant polyphenols called ellagitannins, which can help reduce oxidative stress (14).

One study showed that when consumed as a drink with other berries, raspberries reduced oxidative stress caused by exercise in cyclists (15).

Raspberries may also increase leptin, a hormone that makes you feel full (16).

The most commonly consumed raspberries are the American red or European red varieties. However, there are many different types of raspberries, and black raspberries have been shown to have a number of health benefits, too.

Black raspberries may be especially good for heart health. Studies have proven that black raspberries can reduce risk factors for heart disease, such as blood pressure and blood cholesterol (17, 18, 19).

Other studies have shown that black raspberries may reduce inflammation in people with metabolic syndrome and reduce the size of polyps in the colon. Polyps are abnormal cell growths that can lead to cancer (20, 21).

However, these studies were very small. More research is needed to confirm the benefits of black raspberries.

Summary: Raspberries are full of fiber and antioxidant polyphenols. Black raspberries, in particular, may benefit heart health.

Goji berries, also known as wolfberries, are native to China and used in traditional medicine. They have recently become very popular in the Western world.

Goji berries also contain high levels of vitamin A and zeaxanthin, both of which are important for eye health.

One study of 150 elderly people found that eating 14 grams of goji berries per day prevented decline in eye health due to aging. This study, along with a second similar study, have shown that eating goji berries can raise blood zeaxanthin levels (23, 24).

Like many other berries, goji berries contain antioxidant polyphenols. One study found that eating goji berries for 30 days increased blood antioxidant levels of healthy, older Chinese people (25).

Another study found that drinking goji berry juice for two weeks increased metabolism and reduced waist size in overweight people (26).

Summary: Goji berries are particularly rich in nutrients that contribute to eye health. They also contain important antioxidants.

Strawberries are one of the most commonly consumed berries in the world and also one of the best sources of vitamin C.

Strawberries are good for heart health. In fact, a study of over 93,000 women found that those who ate more than three portions of strawberries and blueberries per week had over a 30% lower risk of heart attack (28).

Other studies have shown that strawberries may reduce a number of risk factors for heart disease including blood cholesterol, triglycerides and oxidative stress (29, 30, 31, 32).

Strawberries can also reduce inflammation by lowering inflammatory chemicals in the blood, such as IL-1β, IL-6 and C-reactive protein (CRP) (33, 34, 35).

In fact, a study of over 200,000 people found that eating strawberries could reduce type 2 diabetes risk by as much as 18% (36).

Finally, another study showed that eating two ounces (60 grams) per day of freeze-dried strawberry powder reduced oxidative stress and inflammatory chemicals in people at high risk of developing esophageal cancer (37).

Summary: Strawberries are an excellent source of vitamin C. They are proven to reduce risk factors for heart disease and help control blood sugar.

Bilberries are very similar to blueberries, and the two are often confused. Bilberries are native to Europe, whereas blueberries are native to North America.

Keep in mind that acai berries are often consumed dried or freeze-dried, which can affect the nutritional content.

Acai berries are one of the best sources of antioxidant polyphenols and may contain as much as ten times more antioxidants than blueberries (46).

When consumed as a juice or pulp, acai berries can increase blood antioxidant levels and reduce chemicals involved in oxidative stress (47, 48).

Additionally, acai berry pulp has been shown to reduce blood sugar, insulin and blood cholesterol levels in overweight adults who consumed 200 grams per day for one month. However, this was in a very small study of only ten people (49).

These effects have also been shown in athletes. Drinking three ounces (100 ml) of an acai juice blend for six weeks reduced blood cholesterol and reduced oxidative stress after exercise, which may help prevent muscle damage (50).

Although acai berries may have benefits for reducing blood cholesterol, other studies have shown that they don’t have any strong effect on reducing blood pressure (51).

The antioxidants in acai may help reduce pain, too. A study of people with osteoarthritis found that drinking four ounces (120 ml) of acai juice per day for 12 weeks significantly reduced pain and improved daily living (52).

Summary: Acai berries contain high amounts of antioxidants, which may help reduce blood cholesterol, oxidative stress and even reduce pain.

Cranberries are an extremely healthy fruit with a sour taste.

They are rarely eaten raw. Instead, they are commonly consumed as juice.

Like many other berries, cranberries also contain antioxidant polyphenols. However, most of these antioxidants are in the skin of the cranberry. Therefore, cranberry juice does not contain as many polyphenols (54).

H. pylori is a type of bacteria that can cause stomach ulcers and cancer. A number of studies have shown that cranberry juice can prevent H. pylori from attaching to the stomach wall and thus prevent infection (61, 62).

Cranberry juice has also shown various benefits for heart health. Many studies have found that drinking cranberry juice can reduce cholesterol, blood pressure, oxidative stress and “stiffness” of arteries (63, 64, 65, 66).

However, it is best to avoid varieties of cranberry juice with lots of added sugar.

Summary: Cranberries and cranberry juice are effective at preventing urinary tract and stomach infections and may benefit heart health. However, it is best to avoid juices with lots of added sugar.

Grapes are widely consumed either as whole, raw fruit or as juice, wine, raisins or vinegar.

The skin and seeds of grapes are an excellent source of antioxidant polyphenols. A number of studies have shown that grape seed polyphenol extracts can lower both blood pressure and heart rate (68, 69).

However, many of these studies were small. Other studies assert that the effect of polyphenols on blood pressure remains unclear (70).

A large observational study found that eating grapes or raisins three times per week was associated with a 12% reduction in risk of type two diabetes (71).

Another study found that eating 17 ounces (500 grams) of grapes per day for eight weeks reduced blood cholesterol and oxidative stress in people with high cholesterol (72).

Finally, grape juice may even benefit brain health. A small study of 25 women found that drinking 12 ounces (355 ml) of grape juice every day for 12 weeks significantly improved memory and driving performance (73).

Summary: Grapes, particularly the seeds and skin, are full of antioxidants. They may help reduce blood cholesterol and type 2 diabetes risk while also benefiting brain health.

Berries are some of the healthiest foods you can eat, as they are low in calories but high in fiber, vitamin C and antioxidants.

Many berries have proven benefits for heart health. These include lowering blood pressure and cholesterol, while reducing oxidative stress.

They may also help reduce the risk of type 2 diabetes by acting as great alternatives to sugary snacks.

Try to eat a few portions of berries a week and sample different types. They make a great snack or healthy breakfast topping.